This part of IEC 60947 specifies requirements for protective conductor terminal blocks with PE function up to 120 mm2 (250 kcmil) and for protective conductor terminal blocks with PEN function equal to and above 10 mm2 (AWG 8) with screw-type or screwless-type clamping units, primarily intended for industrial applications. NOTE AWG is the abbreviation of “American Wire Gage” [Gage (US) = Gauge (UK)] kcmil = 1 000 cmil 1 cmil = 1 circular mil = surface of a circle having a diameter of 1 mil 1 mil = 1/1 000 inch Protective conductor terminal blocks are used to form the electrical and mechanical connection between copper conductors and the fixing support. lt is applicable to protective conductor terminal blocks for the connection of round copper conductors with or without special preparation having a cross-section between 0,2 mm2 and 120 mm2 (AWG 24 and 250 kcmil), intended to be used in circuits of a rated voltage not exceeding 1 000 V a.c. up to 1 000 Hz or 1 500 V d.c., most commonly in conjunction with terminal blocks according to IEC 60947-7-1. This standard may be used as guide for − protective conductor terminal blocks requiring the fixing of special devices to the conductors, for example quick connect terminations or wrapped connections, etc.; – protective conductor terminal blocks providing direct contact to the conductors by means of edges or points penetrating the insulation, for example insulation displacement connections, etc. Where applicable in this standard, the term “clamping unit” has been used instead of the term “terminal”. This is taken into account in case of reference to IEC 60947-1.